Help to identify LED offline driver

I need to identify failed LED driver, which has very poor markings. I’m curious because it’s a nice design - feeds 40mA into 136 3528 LEDs (68 pairs, no resistors) directly from 120V AC. Perhaps someone can tell the manufacturer by its logo? Attaching 3 images


Welcome to the technical forum. I am sorry. I am not able to verify who this is. Though being on the forum, this will be reviewed and maybe someone will have an idea. I did some general searches and was not able to verify who made this . I also could not find anyting in our system doing a search.

1 Like

Hello @aaroutio ,

Thank you for your inquiry. The manufacturer logo looks like ‘JW’? I am also unable to read the part markings, if you are able to identify the markings this would help - a Loupe may help with this. I wasn’t able to locate any 40mA drivers, but depending on the design they may have the output buffered through another chip which would provide the 40mA instead of the driver itself.

Click here for similar packaged drivers that you may want to look over. Please review datasheet specifications as it is unknown if these will work for your application. These are rated for 120V AC, but if you find out there is a bridge rectifier leading up to the driver chip, then we would have to look at all of the DC voltage options instead.

Hi Ryan,

Attached is the schematics - how this driver is used in this specific application.

As you can see, this driver has internal switch, and no other switching components.
Looks like this driver should be able switching 240V (the working voltage on the output side).

I’ve been going through the drivers on the DigiKey site, it is slow as it requires opening the pdf data sheet for each, and so far I haven’t found any application like mine. The solution looks very sleek, that’s why I got interested in it.

I’ll try the 20x loupe, maybe I can find a good angle to read the markings.

Thank you!

I’m pretty sure the manufacturer is joulwatt. Also, I think the chip itself is a JW1758B LED driver.

Hi @slycer2002 ,
That looks like the correct chip. Below are the most similar options we carry but appear to have differences:
LED Drivers

Fortunately it looks like the original chip can be purchased online.

Cool, thank you guys!

1 Like

It is JW1756B JW1756B (

Now the question is - where to order it. All usual places like DigiKey, Mouser, Newark - don’t have it. Aliexpress, eBay - not. I asked Joulwatt in the email. Meanwhile, any suggestions?

I do not find any outside sources for their product.

still do not find a direct cross

1 Like

I found them @ Amazon

It is JW1756B, not 1758B. This is pretty unique driver. In theory it can feed stable 50mA up to 450V LED strip. If you check Joulwatt site, 1756B is the only LED driver for low current/high voltage feeds.


Have you been able to find a place go get the JW1756B? I need it for a project but I can’t find it. Sent a message to Joulwatt but haven’t gotten any reply.


Welcome to the technical forum. The only place I see this part is the Amazon link:

Thank you Verna for the kind welcome!

The amazon link is for JW1758B. But I’m in need of JW1756B. Do you think I can still use JW1758B in place of the JW1756B?

So I went to the website to check on the Joulwatt website also. They will not list the full data sheet unless you register. There is no way to do a ful compare without it. Sorry.

No response from Jollywatt. No Facebook presence. I would say this company is on the way down, if not there already. Pity…

That could be true. Though things have been pretty busy for companies now. I would say give it time. The industry has been busy and it is hard to catch up or even keep up. Hopefully they will respond.

Hi aaroutio,

I wonder, could you disclose the specification for your application (e.g. supply voltage, number and type of LEDs used, desired current, dimming capability requirement, etc.) so that could ponder some alternative solutions to JouleWatt’s.

heke, AsamaLab

My interest was very simple. I have a broken led lamp, and wanted to fix it by replacing the failed component. Hate throwing thing away. And I was also curious about the circuit design - how they did it. I had attached the diagram